▪ Abstract The inactive X chromosome differs from the active X in a number of ways; some of
these, such as allocyclic replication and altered histone acetylation, are associated with all
types of epigenetic silencing, whereas others, such as DNA methylation, are of more
restricted use. These features are acquired progressively by the inactive X after onset of
initiation. Initiation of X-inactivation is controlled by the X-inactivation center (Xic) and
influenced by the X chromosome controlling element (Xce), which causes primary�…